With the rapid progress of wireless technologies and the huge requirements imposed on intelligent control, more and more control systems choose wireless connection as a method of transferring control commands. Such systems are referred to as wireless control systems. For example, centrally controlled illumination networks employing a wireless connection are widely used, and a wireless control system allows a user to wirelessly control the illumination networks for displaying different illumination profiles. However, to make sure that the illumination networks receive wireless control commands and act promptly, wireless devices in the illumination networks need to be permanently active or wake up periodically so as to detect whether a command is received or not received. For example, if a light source in the above-mentioned centrally controlled illumination networks needs to respond to a user's command within one second, its corresponding wireless device must wake up every second. Usually, a wireless device of the wireless control system does not get any command during its wake-up period. Consequently, such illumination networks are less effective in terms of energy.